The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals
The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals
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DOI：
10.1007/s00338-010-0697-z
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发表时间：
2011-06-01
期刊：
影响因子：
3.5
通讯作者：
Dillon, A. B.
中科院分区：
文献类型：
--
作者：
de Putron, S. J.;McCorkle, D. C.;Dillon, A. B.
大气中二氧化碳浓度的上升正在改变海洋的碳酸盐化学，这一过程称为海洋酸化（OA）。表层海洋对二氧化碳的吸收增加了可用于海洋钙化的总溶解无机碳 (DIC) 和碳酸氢根离子 (HCO3 (-)) 的量，同时降低了海水 pH 值和碳酸根离子浓度 ([CO3 (2-)])，从而降低了海水相对文石 (Omega(ar)) 的饱和状态。我们研究了 [HCO3 (-)] 与 [CO3 (2-)] 对于两种热带珊瑚物种 Favia fragum 和 Porites astreoides 的新成员（从虫黄藻幼虫定居的初级息肉）早期钙化的相对重要性。息肉在一系列 Omega(ar) 值范围内饲养，该值通过恒定 pCO(2) 下的酸添加（总 [HCO3 (-)] 和 [CO3 (2-)] 减少）和恒定碱度下的 pCO(2) 升高（[HCO3 (-)] 增加，[CO3 (2-)] 减少）来控制。两周后的钙化通过称重实验过程中每个息肉生长的完整骨骼（珊瑚石）来量化。无论 Omega(ar) 是通过添加酸还是通过 pCO(2) 升高降低，这两个物种都对 [CO3 (2-)] 降低表现出相同的负面反应 - 钙化不遵循总 DIC 或 [HCO3 (-)]。然而，钙化对[CO3(2-)]减少的响应是非线性的。仅在 Omega(ar) = < 2.5 和 Omega(ar) = 1.1-1.5 之间检测到钙化具有统计学意义的显着减少，其中 Omega(ar) 每减少 1.0，新兵的钙化减少 22-37%。我们的结果与许多先前的研究不同，这些研究报告了珊瑚对 OA 的线性钙化反应，也不同于那些显示钙化随着 [HCO3 (-)] 的增加而增加的研究。显然，珊瑚钙化对 OA 的反应是可变且复杂的。需要更深入地了解这些可变反应背后的生物矿化机制和环境条件，以支持对未来OA对珊瑚和珊瑚礁影响的明智预测。
Rising concentrations of atmospheric CO2 are changing the carbonate chemistry of the oceans, a process known as ocean acidification (OA). Absorption of this CO2 by the surface oceans is increasing the amount of total dissolved inorganic carbon (DIC) and bicarbonate ion (HCO3 (-)) available for marine calcification yet is simultaneously lowering the seawater pH and carbonate ion concentration ([CO3 (2-)]), and thus the saturation state of seawater with respect to aragonite (Omega(ar)). We investigated the relative importance of [HCO3 (-)] versus [CO3 (2-)] for early calcification by new recruits (primary polyps settled from zooxanthellate larvae) of two tropical coral species, Favia fragum and Porites astreoides. The polyps were reared over a range of Omega(ar) values, which were manipulated by both acid-addition at constant pCO(2) (decreased total [HCO3 (-)] and [CO3 (2-)]) and by pCO(2) elevation at constant alkalinity (increased [HCO3 (-)], decreased [CO3 (2-)]). Calcification after 2 weeks was quantified by weighing the complete skeleton (corallite) accreted by each polyp over the course of the experiment. Both species exhibited the same negative response to decreasing [CO3 (2-)] whether Omega(ar) was lowered by acid-addition or by pCO(2) elevation-calcification did not follow total DIC or [HCO3 (-)]. Nevertheless, the calcification response to decreasing [CO3 (2-)] was nonlinear. A statistically significant decrease in calcification was only detected between Omega(ar) = < 2.5 and Omega(ar) = 1.1-1.5, where calcification of new recruits was reduced by 22-37% per 1.0 decrease in Omega(ar). Our results differ from many previous studies that report a linear coral calcification response to OA, and from those showing that calcification increases with increasing [HCO3 (-)]. Clearly, the coral calcification response to OA is variable and complex. A deeper understanding of the biomineralization mechanisms and environmental conditions underlying these variable responses is needed to support informed predictions about future OA impacts on corals and coral reefs.